If the books are DRM books you must have already authorized the Galaxy to be able to read the books there; or ???
Most eReaders need to be connected to ADE (Adobe Digital Editions) to be authorized with Adobe ID to permit reading DRM books.
ADE runs only on PC and Mac.
You may have difficulty transferring books to the kobo without a PC or Mac as well;
you might manage it if you can connect so the Galaxxy cas see the files on the kobo.
I haven’t authorised the tablet ………….. I have authorised my computer and Sony Reader but wanted to also move the books on to my tablet as it is bigger.
I can drag and drop the books onto the tablet but when I try to import the files from the SD card the import fails and I’m sure it is happening because of DRM as the tablet doesn’t recognise the books as my purchases.
I don't know what ereader app is preinstalled on the tablet and if it supports Adobe DRM.
You may need to install an appropriate app on the tablet:
I find Bluefire good, some people prefer Aldiko or Overdrive.
When you install Bluefire, it comes up with an option to register your Adobe ID.